Enterprise networks can track locations of wireless devices using radio frequency location tracking techniques. Enterprises can use existing wireless infrastructure such as wireless access points, and sensors to report measurements from which the location of a wireless device can be approximated. Several techniques or combinations of techniques can be used including time of arrival, time difference of arrival, received signal strength, and angle of arrival techniques.
The most common technique utilizes received signal strength (RSS) information. Access points, typically mounted on the ceiling, can receive a signal from a wireless device, typically near ground level (desk surface, in a user's hand or pocket, etc.) and detects the average signal level of transmissions between the wireless device and each access point. The signal level can be used to derive a distance from each access point. An indoor location controller can determine points in which the distances from two or more access points overlap and can thereby determine probable locations that the wireless device might be located. The more access points that provide signal level data pertaining to that wireless device, the more accurately the probable location will match the true location.
While all of the techniques or combinations of techniques listed above perform well in the right circumstance, determining location indoors is a challenge for all of the techniques. Determining location indoors is a challenge due to the fact that the radio frequency environment is influenced by obstacles such as walls, and interference from other radio frequency emitting devices and electronics in the environment.